Vertical fine movement mechanism of microscope

ABSTRACT

An optical microscope of high stability such that the image of a sample does not become obscure during observation, and no movement (drift) of an object point (object) occurs. The optical microscope is characterized by comprising vertical straight movement guide mechanisms ( 4  and  8 ) for an objective lens ( 6 ) of the microscope symmetrical to the optical axis, and fine adjustment units ( 10, 11  and  12 ) for the objective lens.

FIELD OF THE INVENTION

This invention relates to a vertical fine adjustment mechanism (focusingmechanism) for optical microscopes including optical measuringinstruments.

BACKGROUND OF THE INVENTION

A mechanism in which the objective lens moves vertically along theZ-axis is frequently used as the focusing mechanism in conventionaloptical measuring instruments and optical microscopes.

The structure of conventional microscopes is described briefly referringto the drawings. FIG. 4 is a side view of the principal part of amicroscope and FIG. 5 is a plan view of it. In the drawings, (101) is astand, (102) is a support mounted on the stand (101) for free verticalmovement, (103) is a revolver for the objective lens mounted on thesupport, and (104) is the objective lens mounted on the revolver. At thesupport (102), a V-groove (105) for a vertical straight movement guidemechanism is formed on both sides as shown in FIG. 5, and opposite tothis groove, a V-groove (106) for a vertical straight movement guidemechanism is formed on the stand (101), and a roller or a ball (107) isheld between these two grooves. Also, a rack (108) is mounted on thesupport (102), a shaft (110) with a pinion (109) engaging this rack(108) protrudes from the stand, and an operation handle that is notshown is mounted on this protruded portion. When this operation handleis rotated, the pinion (109) is rotated through the shaft (110), therack (108) mounted on the support (102) moves vertically, and also thesupport (102) moves vertically at the same time, allowing the objectivelens (104) mounted on the revolver (103) to be focused.

In the conventional microscopes described above, however, since one endof the one side support type support (102) that is asymmetrical withrespect to the center of the optical axis is moved vertically for fineadjustment by means of the rack-and-pinion mechanism, the vertical finemovement mechanism is remarkably asymmetrical and the operation isunstable. Variations in environmental temperature, in particular, causefluctuations of the center of the optical axis, resulting in theunstable image. Since drift due to temperature changes occurs in such avertical fine movement mechanism, this mechanism cannot be currentlyused for molecular position measurement or molecular motion measurement.

This invention is therefore intended to solve the above problem byrealizing an optical microscope of high stability in which the image ofthe viewed sample does not become out of focus during observation and nomovement (drift) of the object point (object) occurs.

DISCLOSURE OF THE INVENTION

The above objectives of the present invention are achieved by a verticalfine adjustment mechanism for microscopes comprising a triple cylinder,namely an external cylinder, an intermediate cylinder, and anintermediate internal cylinder to which an objective lens can bemounted, with said intermediate cylinder and internal cylinder equippedwith vertical straight movement guide mechanisms in equally divideddirections on the circumference and with said internal cylinder equippedwith a means of vertical fine adjustment, wherein said means of verticalfine adjustment is equipped with an interlock pin installed in theintermediate cylinder inverted L-shaped hardware that contacts theinterlock pin and moves it vertically, and an actuator that actuates theinverted L-shaped hardware. Said means of vertical fine adjustment isequipped with an interlock pin (10) installed in the intermediatecylinder (7), inverted L-shaped hardware that is brought into contactwith the interlock pin and moves it vertically, and an actuator thatactuates the inverted L-shaped hardware.

Also, in the vertical fine adjustment mechanism for microscopes, two ofsaid interlock pins may be configured so that uniform strain is appliedto both.

Also, in the vertical fine adjustment mechanism for microscopes, saidactuator may be a micrometer head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of the principal part of a microscoperelating to the first embodiment of this invention.

FIG. 2 is a plan sectional view of the same microscope.

FIG. 3 is a side view of the same microscope

FIG. 4 is a side view of the principal part of a conventionalmicroscope.

FIG. 5 is a plan view of the principal part of a conventionalmicroscope.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the vertical fine adjustment mechanisms formicroscopes relating to this invention are described with reference tothe drawings. FIG. 1 is a side sectional view of said microscope, FIG. 2is a plan sectional view of the same microscope, and FIG. 3 is a sideview of the same microscope.

In the drawings, an external cylinder (2) that has a concentric insidediameter and outside diameter around the central axis is mountedvertically on the substrate (1). At the lower part of the externalcylinder (2), flange (2A) for fastening is formed, and in the insidediameter of the external cylinder (2), an intermediate cylinder (3) isincorporated with very small clearance. Parallel cut-out surfaces (4A)that are parallel to the central axis of this intermediate cylinder (3)and set at equal distances from this central axis are prepared at 120degree intervals, and V-shape groove straight guide hardware (4) ismounted on these cut surfaces so that the hardware can be tightened withfastening screws (5). On the equally three-divided portions of the innercircumference of the intermediate cylinder (3), a rectangular window isopened in which a roller or a ball (8) rolls.

On the equally three-divided portions of the outer circumference of theinternal cylinder (7) to which the objective lens (6) of the microscopecan be mounted by screwing it on, a V-groove in which a roller or a ball(8) rolls is cut.

A vertical straight movement guide mechanism (three-directional straightguide mechanism) with a hollow shaft (optical axis) is configured byassembling these parts. In addition, this mechanism can be configured sothat two of the three V-grooves formed in equally three-divided portionsof the outer circumference of the internal cylinder (7) are squaregrooved (that is, the groove surface is flat), the relevant parts of theintermediate cylinder (3) are planes parallel to the central axis, and aroller is incorporated between them. In this configuration, althoughsymmetry is slightly impaired, the stability is not affected and themanufacturing cost can be reduced.

Also in this configuration, the V-shaped groove straight guide hardware(4) is fastened with screws (9) on the outer circumference of theexternal cylinder (2) at 120 degree intervals to prevent unstablemovement of the intermediate cylinder (3), and to enable pressure to beapplied to the roller or the ball (8).

The mechanism for applying pressure is not limited to the screws (9)described above, and the following configuration can also be adopted. Ifoperating temperature fluctuations exceed several degrees, even ifmaterial of the same thermal expansion coefficient is used, for example,for the intermediate cylinder (3) and the internal cylinder (7), somefluctuation may occur, resulting in fitting instability that exceedsdeformation levels due to pressure or excessive pressure. In this case,a configuration can be adopted in which coil springs and spring housingsare prepared in place of the screws (9) on the external cylinder (2), orplate springs are inserted between the intermediate cylinder (3) and theV-shaped groove straight guide hardware (4), to absorb the fittinginstability caused by operating temperature fluctuations whilemaintaining the symmetry. Also, a coil spring can be used as the spring,and other types of springs that can achieve a similar function can beused in place of the plate spring.

On the other hand, the vertical fine movement mechanism can be comprisedof a means of fine adjustment that is comprised of the interlock pin(10), the micrometer head (11), and a lever with inverted L-shapedhardware. The interlock pin (10) is mounted on the internal cylinder (7)to which the objective lens (6) is mounted, and one side of the invertedL-shaped hardware (12) is brought into contact with this interlock pin.The inverted L-shaped hardware (12) is supported for free rotation inboth directions through the washer (14) by the fixed shaft (13) that ismounted on the outer circumference of the external cylinder (2), and theother side of the inverted L-shaped hardware is brought into contactwith the micrometer head (11). The micrometer head (11) is mounted withthe micro-fixing hardware (15) so that its height is aligned with thatof the inverted L-shaped hardware (12), and the operation of themicrometer head (11) allows one side of the inverted L-shaped hardware(15) to be pressed, the other side of the inverted L-shaped hardware tobe moved upward accordingly, and the interlock pin (10) to be pushed upto move the internal cylinder (7) upward with fine adjustment. Also, therotating section of the inverted L-shaped hardware can be equipped witha return spring if appropriate to enable it to be restored to itsinitial state. In addition, for the micrometer head (11), anotheractuator with a gear motor can be used. Also, the level of fineadjustment can be set freely by adjusting the length of each side of theinverted L-shaped hardware.

The preferred embodiments of this invention are as described above.However, the vertical straight movement guide mechanism is notnecessarily limited to three directions, and other numbers of directionsare possible. Also, other types of vertical fine movement mechanismsthat can realize similar action can be used by changing the shape of thegrooves and the roller.

In addition, this invention can be embodied in many forms withoutdeviating from its purpose or principal features. The preferredembodiments described herein are therefore only examples in all respectsand should not be construed to imply limitations.

INDUSTRIAL APPLICABILITY

The straight guide mechanisms of this invention have symmetricalstructures with respect to their weight and shape, and therefore, amicroscope focusing mechanism with very good balance and high stabilityis achievable.

Since a highly stable optical microscope is realized, measurement ofmolecular position and molecular motion on the order of nanometers inthe fields of molecular biology and biophysics can be easily performed.If an actuator operated on the order of 0.1 micrometer per pulse thathas the high degree of straightness and low torque required for verticalfine movement is used at the micrometer head (10) in the straight guidemechanism, the leverage enables a highly precise and low-cost verticalfine movement mechanism capable of achieving resolutions of 0.02 μm orless.

These effects can be achieved as described above.

1. A vertical fine adjustment mechanism for microscopes comprising atriple cylinder, namely an external cylinder, an intermediate cylinder,and an intermediate internal cylinder to which an objective lens can bemounted, with said intermediate cylinder and internal cylinder equippedwith vertical straight movement guide mechanisms in equally divideddirections on the circumference and with said internal cylinder equippedwith a means of vertical fine adjustment, wherein said means of verticalfine adjustment is equipped with an interlock pin installed in theintermediate internal cylinder, inverted L-shaped hardware that contactsthe interlock pin and moves it vertically, and an actuator that actuatesthe inverted L-shaped hardware.
 2. The vertical fine adjustmentmechanism for microscopes according to claim 1, wherein said actuator isa micrometer head.